Your question seems fairly obvious, but since I've been known to ask a few slap-your-head-after-getting-the-answer questions I'll help you out:

Quote Originally Posted by warpedmind
1 packages upgraded, 0 newly installed, 0 to remove and 125 not upgraded.
Need to get 0B/327kB of archives. After unpacking 332kB will be used.
This is the important part.

"1 packages upgraded" - this means there's a newer version on an install program or library on the server. If you choose to continue, apt-get will automatically download and install the new program or library over the old one.

"0 newly installed" - pretty obvious. There's nothing new that you don't already have.

"0 to remove" - no packages will be removed from your system at this time. This is what you were worried about?

"125 not upgraded" - these packages are current.

"Need to get 0B/327kB of archives. After unpacking 332kB will be used." - This is the total file size of the packages to be grabbed and then how much space they will take up after installation.

Oh, and if you've just installed from the CD you should first do an apt-get update to makes sure you list of package versions is current.